Nude photos of more than 100 A-list celebrities, including Jennifer Lawrence, have been leaked online after reports suggest an anonymous hacker was able to gain access to Apple's online storage system, iCloud.

A 4Chan user posted the trove of photos Sunday night, writing the celebrities were in "various states of undress" in the images. On Monday morning, many of the celebrities were shooting back against the alleged hack.

"Even if you have deleted photos from your phone, often times they've already been uploaded into the cloud, and when you delete them from the phone, they continue to exist," Director of the University of Southern California's Center for Computer System Security Clifford Neuman told ABC News.

A spokesperson for Lawrence, star of the blockbuster The Hunger Games franchise, confirmed in a statement that the actress’s photos are authentic. But the spokesperson had sharp words for anyone thinking about posting the photos.

"This is a flagrant violation of privacy … The authorities have been contacted and will prosecute anyone who posts the stolen photos of Jennifer Lawrence."

Lawyers for Upton, a model and actress, had similar comments saying they "intend to pursue anyone disseminating or duplicating these illegally obtained images to the fullest extent possible."

'Final Destination' actress Mary E. Winstead took to Twitter to voice her anger about the possibility of people looking at her personal photos.

To those of you looking at photos I took with my husband years ago in the privacy of our home, hope you feel great about yourselves.

A number of Twitter accounts that reposted nude photos have been suspended. It is against Twitter's rules for users to post other people's private information or to post obscene or pornographic images.

The 4Chan user claims to have more naked photos and videos and will share them in return for payment. The user claims in a post to not be the hacker, but to be merely a "collector."